For months, a military stalemate has defined the war in Syria. Now, a new strategy is emerging as Western allies and Gulf states step up support for rebels in southern Syria.

Along Jordan's northern border, Syrian rebels say they are unifying their fractious ranks, urged to unite by Western and Arab intelligence operatives who work in a covert command center in Jordan's capital.

Rebel sources confirm pledges of stepped-up deliveries of arms and intelligence sharing. The idea is to support more secular groups in Syria's south, to pressure the Assad regime from rebel strongholds along the southern border.

Saudi Arabia has long been covertly supplying arms to the rebels. "Saudis would like to change the balance of power inside Syria," says Labeeb Kamhawi, a Jordanian analyst. "So the best way to make sure this happens is to make Saudi presence inside Syria on the ground noticeable to everybody."

On a Jordanian highway, more than two dozen trucks line the side of the road. These are Saudi trucks; the sign on the side says, "The Saudi National Campaign — Support for Brothers in Syria."

There is an official logo on each one. These deliveries have gained momentum since talks between the regime and rebels collapsed in Geneva earlier this year.

Sources in Jordan say these trucks are filled with humanitarian aid, and that's what's new: Saudis are now moving humanitarian aid into southern Syria.

It's an open secret. "They don't even bother to hide the fact that they are sending these huge trucks to Syria, because they cannot hide them," Kamhawi says.

In this conflict, food has become a weapon of war. The Syrian regime has denied food and medicine to rebel areas in a tactic international aid groups call "surrender or starve."

A recent UN resolution called on Syria to allow unfettered access to aid, even demanding deliveries across neighboring borders. But so far, the regime has resisted official cross-border operations.

The Saudi deliveries can change the balance on the ground, says a Syrian activist, who withheld his name to protect family still in southern Syria.

"There is no food," he says. "Lots of bakeries are not working, people are getting sick."

He says civilians welcome the food and medicine, but rebels want allies to fulfill a pledge of military support as the regime continues to gain ground.

For now, the rebels get light arms and more anti-tank weapons, U.S. officials say, plus cash for rebel battalions. That has raised hopes for the promise of heavier weapons.

"They think that these promises might be true this time and there is something different with these promises," the activist says.

In Jordan, as the war enters its fourth year, the flow of Syrian refugees remains steady. The overwhelming majority are women and children. The UN's Kilian Kleinschmidt, who runs the Zaatari refugee camp — the largest in Jordan — keeps count.

"We are having every night, 300 to 700 people coming into the camp," Kleinschmidt says. "Of course, it's challenging. The camp is full."

New camps have been opened for an influx that has overwhelmed this country. The Saudi aid openly going to southern Syria could stem some of the tide, but it comes with risks, Kamhawi says.

"If Jordan allows even humanitarian aid to go into Syria without coordinating this with the Syrian government, then the Syrians would look at this as being an act of aggression," he says.

Jordan's covert role as a base for Western and Arab allies arming, training and now openly feeding rebels puts the country on the front line of the war.

For months now, the war in Syria has been stuck in a military stalemate. U.N. envoy Lakhdar Brahimi is in Tehran, trying to get Iran, which is Syria's closest ally and supporter, to re-start peace negotiations with rebels. The last attempt to find a diplomatic solution failed in Geneva when talks between the regime and rebels collapsed earlier this year.

NPR's Deborah Amos reports that a new strategy is emerging, as Western allies and Gulf States step up support for rebels in Southern Syria.

DEBORAH AMOS, BYLINE: Along Jordan's northern border, Syrian rebels say they are unifying their fractious ranks urged to unite by Western and Arab intelligence operatives, who work in a covert command center in Jordan's capital. Rebel sources confirm pledges of stepped-up deliveries of arms and intelligence sharing. The idea is to support more secular groups in the south to pressure the Assad regime from rebel strongholds along Syria's southern border.

Saudi Arabia has long been covertly supplying arms to the rebels. Labeeb Kamhawi is a Jordanian analyst.

LABEEB KAMHAWI: It is known now that the Saudis would like to change the balance of power inside Syria. So the best way to make sure this happens is to make Saudi presence inside Syria on the ground noticeable to everybody.

AMOS: What's new: The Saudi are now moving humanitarian aid into Southern Syria.

(SOUNDBITE OF A VEHICLE)

AMOS: There are more than two dozen trucks on the side of the road here on a Jordanian highway. These are Saudi trucks. The sign on the side says: The Saudi National Campaign For Support For Brothers In Syria. There is an official logo on each one. Sources here in Jordan say they are filled with humanitarian aid on the way into Syria.

(SOUNDBITE OF VEHICLE DRIVING BY)

AMOS: These deliveries have gained momentum since the collapsed of the Geneva talks, according to rebel sources. In Jordan, says Kamhawi, it's an open secret.

KAMHAWI: They don't even bother to hide the fact that they are sending these huge trucks to Syria because they cannot hide them.

AMOS: In the Syrian conflict, food has become a weapon of war. The Syrian regime has denied food and medicine to rebel areas in a tactic international aid groups call Surrender or Starve. A recent U.N. resolution called on Syria to allow unfettered access to aid, even demanding deliveries across neighboring borders. But so far, the regime has resisted official cross border operations. The Saudi deliveries can change the balance on the ground, says this Syrian activist.

UNIDENTIFIED MAN: There is no food. Lots of bakeries are not working. People are getting sick.

AMOS: So the Saudi aid actually does help?

UNIDENTIFIED MAN: It does help. Of course.

AMOS: He does not give his name to protect family still in Southern Syria. He says civilians welcome the food and medicine, but rebels want allies to fulfill a pledge of military support - as the regime continues to gain ground. For now, U.S. officials say the rebels get light arms and more anti-tank weapons, plus cash for rebel battalions. That's raised hopes for the promise of heavier weapons.

UNIDENTIFIED MAN: After they getting salaries, they think that these promises might be true this time and there is something different with these promises.

(SOUNDBITE OF WOMEN AND CHILDREN SINGING)

AMOS: In Jordan, as the war enters its fourth year, the flow of Syrian refugees remains steady. The overwhelming majority are women and children. The U.N.'s Killian Kleinschmidt keeps count. He runs Zaatari refugee camp; it's the largest in Jordan.

KILLIAN KLEINSCHMIDT: We are having every night, three to 700 people coming into the camp. Of course, it's challenging, the camp is full.

AMOS: New camps have been opened for an influx that's overwhelmed this country. The Saudi aid openly going to Southern Syria could stem some of the tide but it comes with risks, says Labeeb Kamhawi.

KAMHAWI: If Jordan allows even humanitarian aid to go into Syria, without coordinating this with the Syrian government, then the Syrians would look at this as being an act of aggression.

AMOS: Jordan's covert role as base for Western and Arab allies arming, training, and now openly feeding rebels puts the country on the front line of the war.